Process for the production of pure caoutchouc.



"tion. Caoutchoucs durin 'tains already coa%ilated caoutchouc.

PATENT OFFICE.

AUGUST FoELsm-e, or OFFENBAlQH-ON-THE-MAIN, GERMANY.

PROCESS FOR THE PRODUCTION OF PURE GAOUTCHOUG.

Specification or Letters Patent.

Application filed September 14,,1eos. Serial No. assert.

To all whom it concem:

Be it known that I, AUGUST FoELsme, a

, subject of the German Em eror, and resident of '10 Komerstrasse, Oenbach-onthe-' Main, Germany, chemist, have invented a certain new anduseful Process for the Production of Pure .Caoutchouc, of which thefollowing is an exact specification.

My invention relates to a new and useful prrocess for the production ofcaoutchouc om plants. The processes-hitherto in use for this purposeproduce neither a' pure nor a particularlyvaluable caoutchouc, theexpense being very great compared with the quality of the materialproduced.

The so-called pure caoutchouc even when freed from resin oilysubstances,fwax and similar materials is very liable to oxidation,

is dark colored, and soon becomes sticky and soft and loses itselasticity.

3A satisfactory caoutchouc must not be too dark'colored and, must onlyhave a small orcentage of resin. Itmust be free from a umen and othersubstances such as glucosides, tannins, i. e; substances liable tofermentafermentation smell very disagreeable an those liable tooxidation become sticky, hard and lose their v elastic pro erties.Furthermore a satisfac-- tory caoutc one must not greatly deterioratewhen washed, must be tenacious and highly elastic. For obtaining such acaoutchouc rough materials which will allow the caoutchouc to coagulateeasiliv within the rinds, leaves, roots, fruits an the like must .be

chosen.'- Firstly the rinds, leaves and the like must be'from trees oryoung caoutchouc plants, which can be best obtained by cultivatingcaoutchouc lants in the same mannor as oak-tan-he ges, from which after-Schum, furthermore some Olitandm kinds come into consideration,especially valuable for the culture i1.- ozimdm Amoldiana (18 Wild andO'litcmdria Nzunde de Wild.

Of the so-called Oaoutchucliam the v valuable Landolfihia domieensisBusse, w was discovered y Dr. Walther Busse in the leguminose-forests ofthe Donde-territory'in the German east-Africa should also be men.-tioned.' Finally for obtaining ure caoutchouc, fruits containing them1st etoe-caoutchouc, maybe used, for example the fruit of thelargefructiferous caoutchouc-mistletoe Strutanthus s r 1i folius Man, ofthe meanfructiferous Pht irusa theobromae (Willd.) Eichl. and the smallfructiferous caoutchouc mistletoe Phthirusa (H. B. K.) EichL,Phomdemi'ron Giord nae Wan-1)., Phoradendron Knoopii Womb. andStrutanthus Roversii Wan-b.

When using root-lianaes and caoutchouclianaes the decorticating may bedispensed with.

When the rinds and the branches-.of the root and caoutchouc-lianaes andof the--m1s'-. been cut in length of about one meter an tied in bundlesthey are tletoe fruits, havin allowed to dry for a short time, thiscausing perfect coagulation of the caoutchouc contained therem. Afterthis the rough material is disintegrated preferaby by means of a disinterator;

T e rough material after disintegration is boiled together with calciumand ma nesium sulfite dissolved in sulfurous' aci (about 10% of therough material) for several hours in closed boiling apparatus eventuallyclosed by lead.

By this operation the coloring matter is destroyed, and tannin or othersubstances are extracted. The lye is removed, and after having beenthoroughly washed, the residue is ut into suitable extraction apparatusand oiledfor several hours together with acetone, methylor ethylalcoholto extract the resin, oily. or wax-hke substances. This ...is continueduntil a sam 1c of the lution leaves.

no residue. In or er to obtain a perfectly pure caoutchouc; the materialrema'imngm the extracting apparatus is now treated with means fordissolving oaoutchouc such as benzol, petroleum-ether, toruol, carbontetra chlorrd,'or similar substances, till a sample of the solventhaving passed the material leaves no residue when evaporated. From thec'aontchouc solution the caoutchouc is now obtained by evaporating thesame in a vacuum or in any other suitable manner. When this is.completed there remains in the appa- 'ratus a perfectly pure,non-oxidizing tenawhich may be separated from each other by mechanicaltreatment such as knurled rollers-Washing-machines, or by wet globular-Washing-machmes Having thus fully described the nature of my invention,what-I desire to secure by Letters Patent of the UnitedStates is 1.Process for the roduction of pure caoutchouc from caoutc ouc plantsconsisting in treating the disintegrated raw material with a hotsolution of the sulfid of an alkaline earth metal in sulfurous acid,treatin the partly purified product with an alcoho and then treating theremaining material with a hydrocarbon for dissolving thecaoutchouc andeva oratingsaid hydrocarbon for obtaining the dissolved pure caoutchouc.

2. Process for the roduction of pure caoutchouc from caoutc ouc lantsconsisting in boiling the disintegrate raw material with a, solution ofcalcium and magnesium sulfid in sulfurous acid, treatin the partlypurified substance ith an a cohol, dissolving the pure caoutc one in theremaining product in naphtha and evaporating off the solvent for thepurpose of securing said pure caoutchouc.

In Witness whereof I have hereunto set my hand in the presence of twowitnesses.

AUGUST FOELSING. Witnesses:

OTTO W. HELLMRICH, IbA' CHR. HAFERMANN.

